Jack Nicholson's 'glandular' women

Jack Nicholson says the difference between men and women is "glandular".

The 70-year-old actor - famed for bedding a host of beautiful ladies half his age - insists "fashionable" theories about the psychological differences between the sexes have no founding.

He confusingly said: "These issues between men and women are not psychological. Look, remember what a gland is. Most of these are glandular issues. A gland is what allows that mother to lift that truck off a child. Whatever intelligent design is, it's not going to leave the continuation of the human species up to fashion crazy, flitting mentalities. It's in those glands."

'The Departed' star also offered his unique musing on why the 'honeymoon period' of relationships only lasts for 18 months.

He added to Parade.com: "The infatuation cycle of 18 months hasn't changed a lot since the monkeys. Look at the numbers. Eighteen months is nine months doubled. A woman's entire system is set so that when you're having that procreative act with a woman, you're dealing with a being whose actual cycle is nine months. It doesn't have to do with her brain. It has to do with her entire bodily system, which is there to overcome the brain. We don't legislate for this stuff. We don't out-think it. You cannot change these fundamental things that we are as human beings - but you can adjust to it."